During work by a work vehicle, existing topography varies with progress of the work. Therefore, existing topography data should be obtained in parallel to progress of the work. Measurement of a distance by a stereo camera is available as one of means for obtaining existing topography data.
An earth-moving machine including a stereo camera having a first image pick-up portion and a second image pick-up portion and image pick-up direction changing means capable of changing a direction of image pick-up by the stereo camera has conventionally been proposed (see, for example, Japanese Patent Laying-Open No. 2013-36243 (PTD 1)). In addition, an earth-moving machine obtaining a stereo image from a plurality of stereo cameras attached to a vehicular body has been proposed (see, for example, Japanese Patent Laying-Open No. 2014-215039 (PTD 2)).
PTD 2 discloses a technique for determining a position of an obstacle over a wide range by attaching a plurality of stereo cameras each configured with two cameras in synchronization with each other to a vehicular body at a prescribed distance from each other.